The cost of wind is, simply enough, what you actually need to spend to generate the electricity. The graph below shows how these costs have changed over the past decade: a long, slow decline as technology improved, followed, over the past 3 years, by an increase as the cost of commodities (in the case of wind, mainly steel) increased, and as strong demand for turbines allowed the manufacturers (or their subcontractors) to push up their prices:
The most recent Energy Outlook by the International Energy Agency suggests that wind power currently costs €60/$80 per MWh, which makes it, today, pretty close to what the traditional generation sources (nuclear, coal, gas) cost:
http://www.dailykos.com/storyonly/2009/5/2/727113/-The-cost-of-wind,-the-price-of-wind,-the-value-of-windWind and also solar are superior, not only for their greenism, but because no enemy force can come take the light or the breeze and the generator itself is simpler than a combustion plant.
